A 50.0 -kg crate is suspended between the floor and the...

A 50.0 -kg crate is suspended between the floor and the ceiling using two spring scales, one attached to the ceiling and one to the floor. If the lower scale reads $120 \mathrm{N},$ what is the reading of the upper scale? Ignore the weight of the scales.

Key Concepts

Free-Body Diagram

A free-body diagram is a simplified sketch that depicts all the forces acting on a single object isolated from its environment. It is an essential tool for visualizing and identifying forces such as gravity, tension, and normal forces, which then allows for the application of force balance equations to predict or analyze the system’s behavior.

Spring Scale Operation

Spring scales measure force based on the extension or compression of a spring, following Hooke’s law. In a system where spring scales are used to measure forces, each scale indicates the magnitude of the force it is applying or experiencing. Understanding how these readings relate to the overall force balance is key to solving problems involving tension and equilibrium.

Force Balance

Force balance involves setting the algebraic sum of forces acting on each object equal to zero, as required for equilibrium. By analyzing the upward and downward forces acting on an object, one can relate unknown forces to known forces like weight, ensuring all forces cancel out in accordance with Newton’s first law.

Static Equilibrium

Static equilibrium is the condition in which an object remains at rest because the sum of all forces acting on it equals zero. In any mechanical system at static equilibrium, the net force in every direction is balanced; this concept allows us to analyze how individual forces (such as gravitational forces and contact forces) add up to maintain a system in a steady state.

Transcript

Please give Ace some feedback